The present invention relates to the field of ambulatory and non-invasive monitoring of an individual""s physiological parameters. In particular, the invention relates to a monitoring apparatus with an improved apparel worn by a monitored individual, the apparel having attached sensors for monitoring parameters reflecting pulmonary function, or parameters reflecting cardiac function, or parameters reflecting the function of other organ systems. The invention also includes systems for receiving, storing, and processing physiological-parameter data, and for making it available to the individual and to health care providers.
In the following, the term xe2x80x9cplethysmographyxe2x80x9d (and its derivative words) means measurement of a cross-sectional area of the body, such as a cross-sectional area of the chest or of the abdomen, or a body part, such as a cross-sectional area of the neck or of an arm. (This meaning is somewhat more limited than is standard in the medical arts.) Further, the phrase xe2x80x9cinductive plethysmographyxe2x80x9d means herein plethysmographic measurements which depend on inductance determinations.
Measurement of pulmonary and cardiac physiological parameters by means of inductive plethysmography is known. For example, many measurement methods and apparatus are disclosed in the following U.S. patents, the entire disclosures of which are incorporated herein, in their entireties, by reference, for all purposes.
(1) The ""872 patent: U.S. Pat. No. 4,308,872, issued Jan. 5, 1982 and titled xe2x80x9cMethod and Apparatus for Monitoring Respiration,xe2x80x9d discloses a method and apparatus for monitoring respiration volumes by measuring variations in the patient""s chest cross sectional area, or variations in both chest and abdomen cross sectional areas, each area being measured by determining the inductance of an extensible electrical conductor closely looped around the body, and the measurements being calibrated by measuring the area variations for a few breaths while directly measuring corresponding volumes of breath, preferably while the patient assumes at least two body positions, for example sitting and supine.
(2) The ""534 patent: U.S. Pat. No. 4,373,534, issued Feb. 15, 1983 and titled xe2x80x9cMethod and Apparatus for Calibrating Respiration Monitoring System,xe2x80x9d discloses methods and systems in which respiration volume is determined by weighting signals representing abdominal and chest cross-sectional areas, where the weighting factors are determined by a procedure involving measuring respiration volume by an alternate measuring apparatus along with unweighted chest and abdomen signals, the measurements occurring for a first series of breaths based with a first relative chest and abdominal contribution and for a second series of breaths based on a second relative chest and abdominal contribution.
(3) The ""252 patent: U.S. Pat. No. 4,452,252, issued Jun. 5, 1984 and titled xe2x80x9cNon-invasive Method for Monitoring Cardiopulmonary Parameters,xe2x80x9d discloses a method for monitoring cardiopulmonary events by inductive plethysmographic measurement of a cross-sectional area of the neck, and further discloses a method for monitoring mouth volume by inductive plethysmographic measurement of a cross-sectional area of the head in a plane which extends through the mouth.
(4) The ""015 patent: U.S. Pat. No. 4,456,015, issued Jun. 26, 1984 and titled xe2x80x9cNon-invasive Method for Semiquantitative Measurement of Neck Volume Changes,xe2x80x9d discloses a method of plethysmographic measurement of a subject""s neck volume by providing an extensible conductor closely circling the neck and, first, calibrated against cross-sectional area so that neck volume may be determined from the conductor""s inductance, and also, second, calibrated against invasively-measured intrapleural pressure so that the intrapleural pressure may also be determined from the conductor""s inductance, and also so that intrapleural pressure may also be obtained from measured neck volume.
(5) The ""407 patent: U.S. Pat. No. 4,648,407, issued Mar. 10, 1987 and titled xe2x80x9cMethod for Detecting and Differentiating Central and Obstructive Apneas in Newborns,xe2x80x9d disclosing methods for detecting the presence and origin of apnea in newborns by concurrently monitoring relative movement of the cranial bones (which have been found to move with respiration as a function of intrapleural pressure), preferably by a surface inductive plethysmographic transducer, and nasal ventilation, preferably by a nasal cannula, thermistor, thermocouple or CO2 sensor, wherein absence of changes in both cranial bone movement and respiratory air flow at the nose indicates of the presence of central apnea, while absence of nasal air flow accompanied by continuing cranial bone movements indicates of obstructive apnea.
(6) The ""962 patent: U.S. Pat. No. 4,777,962, issued Oct. 18, 1988 and titled xe2x80x9cMethod and Apparatus for Distinguishing Central Obstructive and Mixed Apneas by External Monitoring Devices Which Measure Rib Cage and Abdominal Compartmental Excursions During Respiration,xe2x80x9d discloses an apparatus and method for distinguishing between different types of apneic episodes. The method includes measuring a new index, Total Compartmental Displacement/Tidal Volume (TCD/VT), and measuring the phase relation between the abdominal and rib cage contributions to total respiration volume, wherein an episode is classified as central, obstructive or mixed based on the value of TCD/VT and the phase relation.
(7) The ""640 patent: U.S. Pat. No. 4,807,640, issued Feb. 28, 1989 and titled xe2x80x9cStretchable Band-type Transducer Particularly Suited for Respiration Monitoring Apparatus,xe2x80x9d discloses an improved, low-cost stretchable band incorporating a conductor for disposition about the human torso or other three dimensional object, and particularly intended for use with respiration monitoring by means of inductive plethysmography, a method for making the band, which method is suitable to mass production techniques, and an improved enclosure housing circuitry releasably connected to the conductor in the band when the band is incorporated in respiration monitoring apparatus.
(8) The ""473 patent: U.S. Pat. No. 4,815,473, issued Mar. 28, 1989 and titled xe2x80x9cMethod and Apparatus for Monitoring Respiration,xe2x80x9d discloses a method and apparatus for monitoring respiration volumes by inductive plethysmographic measurement of variations in a patient""s chest cross sectional area, or preferably, variations in both chest and abdomen areas during breathing, and a method for calibrating such an apparatus by measuring cross-sectional area variations for a few breaths while directly measuring corresponding volumes of breath, preferably while the patient assumes at least two body positions, for example sitting and supine.
***(9) The ""766 patent: U.S. Pat. No. 4,860,766, issued Aug. 29, 1989 and titled xe2x80x9cNoninvasive Method for Measuring and Monitoring Intrapleural Pressure in Newborns,xe2x80x9d discloses measuring intrapleural pressure of a newborn subject by detecting relative movement between adjacently-proximate cranial bones, preferably, using a surface inductive plethysmographic transducer secured on the subject""s head across at least two adjacently-proximate cranial bones, and a method of calibrating such measurements by temporarily manually occluding the subject""s nose or, if intubated, the endotracheal tube, to measure the airway pressure during such occlusion as the subject makes an inspiratory effort and comparing the measured pressure to the measured signal.
(10) The ""109 patent: U.S. Pat. No. 4,834,109, issued May 30, 1989 and titled xe2x80x9cSingle Position Non-invasive Calibration Technique,xe2x80x9d discloses an improved method for calibrating inductive plethysmographic measurement of respiration volume by totaling, during a period of breathing, a plurality of values of a parameter indicative of the relative amplitude, for each breath, of uncalibrated rib cage and abdomen signals, and by dividing the average variability of the means of the total of the values of one of the rib cage and abdomen signals by the average variability of the mean of the total of the values of the other signal, the quotient being so derived represents a signal weighting factor for determining respiration volume.
(11) The ""277 patent: U.S. Pat. No. 4,986,277, issued Jan. 22, 1991 and titled xe2x80x9cMethod and Apparatus for Non-invasive Monitoring of Central Venous Pressure,xe2x80x9d discloses a method and apparatus for measuring central venous pressure (CVP) and changes in CVP along with an improved transducer (50) for measuring CVP in infants, wherein a plethysmographic transducer is disposed on the neck of a subject (or on the head in the case of infants), the signal from the transducer is processed to obtain a cardiac component, and the vertical distance from the transducer to a reference level is adjusted until a position is located at which the signal changes between a venous configuration and an arterial or mixed venous-arterial configuration, at which position the vertical distance approximates CVP.
(12) The ""540 patent: U.S. Pat. No. 5,040,540, issued Aug. 20, 1991 and titled xe2x80x9cMethod and Apparatus for Non-invasive Monitoring of Central Venous Pressure, and Improved Transducer Therefor,xe2x80x9d discloses an improved method and apparatus for measuring central venous pressure (CVP), and changes in CVP, along with an improved transducer for measuring CVP in infants.
(13) The ""935 patent: U.S. Pat. No. 5,159,935, issued Nov. 3, 1992 and titled xe2x80x9cNon-invasive Estimation of Individual Lung Function,xe2x80x9d discloses a non-invasive method and apparatus for plethysmographic monitoring individual lung function by disposing a transducer on the torso above the lung to be monitored, the transducer producing a signal corresponding to movement of the torso portion there beneath which, in turn, corresponds to changes in the volume of the underlying lung, and also a method and apparatus for monitoring regional lung volume changes by utilizing transducers positioned on the torso to encompass only a portion of the underlying lung.
(14) The ""151 patent: U.S. Pat. No. 5,178,151, issued Jan. 12, 1993 and titled xe2x80x9cSystem for Non-invasive Detection of Changes of Cardiac Volumes and Aortic Pulses,xe2x80x9d discloses a method and an apparatus therefor for monitoring cardiac function in an animal or human subject including the steps of placing a first movement detecting transducer on the torso, said transducer overlying at least part of two diametrically opposed borders of the heart or great vessels; generating a signal indicative of the movement of the torso portion subtended by the transducer, said signal including a cardiac component comprising at least a segmental ventricular volume waveform or a segmental aortic pressure pulse waveform and assessing cardiac function by monitoring changes in said ventricular volume waveform or said aortic pressure pulse waveform.
(15) The ""678 patent: U.S. Pat. No. 5,301,678, issued Apr. 12, 1994 and titled xe2x80x9cStretchable Band-Type Transducer Particularly Suited for Use with Respiration Monitoring Apparatus,xe2x80x9d an improved, low-cost stretchable band incorporating a conductor for disposition around the human torso or other three-dimensional object, and particularly intended for use with plethysmographic respiration monitoring apparatus, is disclosed.
(16) The ""968 patent: U.S. Pat. No. 5,331,968, issued Jul. 26, 1994 and titled xe2x80x9cInductive Plethysmographic Transducers and Electronic Circuitry Therefor,xe2x80x9d discloses an apparatus and method for improving the detection of the inductance xe2x80x9csignalxe2x80x9d generated by an inductive plethysmograph by modifying the design of the inductive plethysmograph and also by improving the design of the associated circuitry, both of which permit the associated circuitry may be located remotely rather than on the transducer, the improvement including selecting the impedance matching transformer joining an inductive plethysmograph to an oscillator such that the inductance of its primary winding is greater than about ten times the reflected inductance of the inductive plethysmograph and the cable joining it to the transformer, or circling the conductor of the inductive plethysmograph therein around the relevant body portion a plurality of times, or selecting the cable connecting the inductive plethysmograph to the transformer such that the ratio of the diameter of its screen to the diameter of its center conductor is minimized for reducing the inductance per unit length thereof.
(17) The ""425 patent: U.S. Pat. No. 5,588,425, issued Dec. 31, 1996 and titled xe2x80x9cMethod and Apparatus for Discriminating Between Valid and Artifactual Pulse Waveforms in Pulse Oximetry,xe2x80x9d discloses a method and apparatus for use in pulse oximetry for discriminating between valid pulse waveforms, determined with a photoelectric plethysmograph, from which arterial oxygen saturation levels are accepted, and artifactual pulse waveforms, from which saturation levels are rejected, according to whether the systolic upstroke time of each pulse waveform is within a predetermined range, it having been discovered that systolic upstroke times for valid pulse waveforms are in a consistent, narrow range which varies only slightly from subject to subject and which may be defined empirically for each subject or established by a default setting applicable to all subjects,
(18) The ""388 patent: U.S. Pat. No. 6,015,388, issued Jan. 18, 2000 and titled xe2x80x9cMethod for Analyzing Breath Waveforms as to Their Neuromuscular Respiratory Implications,xe2x80x9d discloses a method for measuring respiratory drive by determining a peak inspiratory flow and a peak inspiratory acceleration from a breath waveform derived from rib cage motion and abdominal motion measured by external respiratory measuring devices, such as those based on inductive plethysmography, the measured respiratory drive being usable to initiate inspiration by a mechanical ventilator and for determining an index describing a shape of the waveform for controlling a continuous positive air pressure (CPAP) device.
(19) The ""203 patent: U.S. Pat. No. 6,047,203, issued Apr. 4, 2000 and titled xe2x80x9cPhysiologic Signs Feedback System,xe2x80x9d discloses a non-invasive physiologic signs monitoring device which includes a garment, in a preferred embodiment, a shirt, with electrocardiogram electrodes and various inductive plethysmographic sensors sewn, embroidered, embedded, or otherwise attached to the garment with an adhesive, signals generated by the sensors being transmitted to a recording/alarm device where they are logged and monitored for adverse or other preprogrammed conditions, which is signaled by When an adverse condition or other preprogrammed condition occurs, a message is communicated to the patient by either an audio message or a display. The recording/alarm unit is also connectable to a remote receiving unit for monitoring by a health care professional or other machine.
However, nowhere in the art of inductive plethysmography are found teachings of practical and effective apparatus for non-invasive, ambulatory monitoring, of pulmonary and cardiac parameters. Such practical and effective monitoring apparatus would be of great benefit by assisting the transfer of health care from traditional hospital-based care, which is administered by trained health care workers, to home-based self care, which is administered by the individual patient during, if possible, the patient""s normal daily activities. This transfer in health care has been found socially desirable because it may reduce health care costs and may increase patient involvement in and commitment to their treatment plans. Non-invasive and ambulatory monitoring apparatus may assist this transfer, because it eliminates the risks associated with invasive sensors placed within the body, such as intravascular catheters, risks which are considerably heightened outside of the hospital.
Citation or identification of any reference in this Section, including the patents listed above, or in any section of this application shall not be construed that such reference is available as prior art to the present invention.
The present invention has for its objects practical and effective apparatus for non-invasive and ambulatory monitoring of key pulmonary and cardiac parameters along with a system that may be used for interpretation and use of monitoring data to improve health care outcomes and to reduce health case costs. In preferred embodiments, the preferred apparatus is a garment which, while including inductive plethysmographic and other physiologic sensors, is sufficiently comfortable and unobtrusive to be worn for most activities of daily life.
In more detail, in a first embodiment, the present invention includes a monitoring apparatus for non-invasively monitoring physiological parameters of an individual comprising: a monitoring garment comprising a shirt for the torso of the individual to be monitored, one or more inductive plethysmographic (IP) sensors, each IP sensor comprising an inductance sensor including at least one conductive loop arranged to closely encircle the torso, wherein the inductance of the conductive loop is responsive to the cross-sectional area of the torso enclosed by the loop, a cardiac cycle sensor for generating signals responsive to occurrence of cardiac ventricular contractions, a signal cable for carrying signals from the sensors, and a microprocessor unit comprising a microprocessor for receiving signals from the signal cable and for recording digital data derived from all received signals in a removable computer-readable memory media.
In first aspects of the first embodiment, the cardiac cycle sensor comprises at least one electrocardiogram (ECG) electrode attached to the individual to be monitored; the cardiac cycle sensor comprises at least one IP sensor closely fitting about the neck of the individual to be monitored, wherein signals the inductance of the IP sensor is responsive to cardiac ventricular contractions because the cross-sectional area of the neck is responsive to carotid artery pulsations generated by cardiac ventricular contractions and the inductance of the IP sensor is responsive to the cross-sectional area of the neck; the computer-readable medium comprises a magnetic disk; the computer-readable medium comprises a flash memory module (64 MB or more).
In second aspects of the first embodiment, the monitoring garment further comprises a band for the neck of the individual to be monitored, and the IP sensors comprise a neck inductive plethysmographic sensor operatively arranged for generating signals responsive to jugular venous pulse, carotid arterial pulse, respiration-related intra-pleural pressure changes, contraction of neck muscles, and swallowing deflections, and the signal cable further comprises an attachment to the conductive loop of the neck IP sensor; the IP sensors comprise at least one abdominal IP sensor including one or more conductive loops and at least one rib cage IP sensor including one or more conductive loops operatively arranged for measuring breathing patterns of the patient; the IP sensors comprise at least one thoracic IP sensor including a two or more conductive loops operatively arranged for measuring ventricular stroke volume; the IP sensors comprise at least one lower abdominal IP sensor operatively arranged for measuring intra-lower-abdominal contractions and dilations; the IP sensors comprise at least one two hemithoracic IP sensors operatively arranged for measuring breathing and paradoxical motion between two hemithoraces of the patient.
In third aspects, the first embodiment further comprises one or more further sensors attached to the signal cable and selected from a group comprising a body position sensor for indicating a posture of the individual, a pulse oximeter for indicating arterial oxygenation saturation, and a throat microphone for indicating talking and snoring; or at least two body position sensors, a first body position sensor mounted on the garment and a second body position sensor mounted on a thigh of the individual; and the IP inductive plethysmographic sensors are attached to the garment as an integral part of the garment via an attachment consisting of one of sewing, embroidering, embedding, weaving and printing the inductive plethysmographic sensor into the garment; the microprocessor unit further comprises an audio device for generating audio indications to the individual being monitored; the microprocessor unit further comprises a display unit for displaying viewable messages to the individual being monitored; the microprocessor unit further comprises an input unit for the individual being monitored to input information or commands to the microprocessor unit.
In fourth aspects of the first embodiment, the microprocessor unit further comprises a memory accessible to the microprocessor, and wherein the memory comprises encoded software instructions for causing the microprocessor to read input data and to write output data derived from the input data in the removable computer-readable memory media; the memory further comprises encoded software instructions for causing the microprocessor to determine significant physiological events in the individual being monitored and to indicate audibly determined significant events to the individual; the microprocessor unit comprises components for wirelessly transmitting determined events and the memory further comprises encoded software instructions for causing the microprocessor to determine significant temporal physiological trends in the individual being monitored and to indicate audibly determined significant trends to the individual; the microprocessor unit comprises components for wirelessly transmitting determined significant trends; the memory further comprises encoded software instructions for causing the microprocessor to compress data before writing to the removable computer-readable memory media.
In fifth aspects of the first embodiment, the microprocessor unit further comprises circuitry for deriving digital data from non-digital data received from the signal cable; the monitoring apparatus further comprises circuitry for generating a variable-frequency signal from each IP sensor, the generated frequency being responsive to the inductance of the conductive loop of the IP sensor, and wherein the microprocessor unit further comprises circuitry for deriving digital data from the generated variable-frequency signals, the digital data comprising encoding of the variable frequency of the signals with errors of 100 ppm or less.
In a second embodiment, the present invention includes a monitoring apparatus for non-invasively monitoring physiological parameters of an individual comprising: a monitoring garment comprising a shirt for the torso of the individual to be monitored, one or more inductive plethysmographic (IP) sensors, each IP sensor comprising (i) a longitudinal band of elastic material attached to the garment for closely encircling the torso, (ii) an inductance sensor including at least one flexible conductive loop attached to the longitudinal band, wherein the inductance of the conductive loop is responsive to the cross-sectional area of the torso enclosed by the loop, and (iii) a tightening device for adjusting circumferential tightness of the IP sensor to substantially prevent longitudinal movement of the IP sensor along the torso, and a microprocessor unit comprising a microprocessor for receiving signals from the IP sensors and for recording digital data derived from all received signals in a removable computer-readable memory media.
In first aspects of the second first embodiment, longitudinal motion of each IP sensor is substantially prevented when the physiological parameters indicated by the inductance of the conductive loop of the sensor do not measurably change; the monitoring garment comprises excess fabric arranged to permit longitudinal stretching of the torso without applying force to the IP sensors sufficient to cause substantial longitudinal motion; longitudinal motion of each IP sensor is substantial if physiological parameters indicated by the inductance of the conductive loop of the sensor change as the monitoring garment is worn by the individual; the monitoring garment comprises fabric with sufficient longitudinal elasticity to permit longitudinal stretching of the torso without applying force to the IP sensors sufficient to cause substantial longitudinal motion.
In second aspects of the second embodiment, the tightening device comprises a cinch band and a gripping device for releasably gripping excess cinch band under tension; the tightening device comprises a drawstring;
In third aspects, the second embodiment, comprises a cardiac timing sensor for generating signals responsive to cardiac ventricular contractions, and wherein the microprocessor unit further records digital data derived from signals received from the cardiac timing sensor; or a signal cable for carrying signals from the sensors to the microprocessor unit.
In a third embodiment, the present invention includes a monitoring apparatus for non-invasively monitoring physiological parameters of an individual comprising: a monitoring garment comprising a shirt for the torso of the individual to be monitored and a longitudinal fastener for opening and closing the shirt, one or more inductive plethysmographic (IP) sensors, each IP sensor comprising an inductance sensor including at least one flexible conductive loop arranged to closely encircle the torso, wherein the inductance of the conductive loop is responsive to the cross-sectional area of the torso enclosed by the loop, a cardiac timing sensor for generating signals responsive to occurrence of cardiac ventricular contractions, a signal cable for carrying signals from the sensors comprising at least one module, wherein the module is coupled to and electrically completes the conductive loops of the IP sensors, wherein termini of the conductive loops may be uncoupled from module, and wherein the module comprises circuitry for generating signals responsive to the IP sensors, and a microprocessor unit comprising a microprocessor for receiving signals from the signal cable and for recording digital data derived from all received signals in a removable computer-readable memory media.
In first aspects of the third embodiment, at least one IP sensor further comprises a tightening device for adjusting circumferential tightness of the IP sensor to substantially prevent longitudinal movement of the IP sensor along the torso, and wherein the tightening device can be arranged not to impede unfastening of the shirt; the conductive loops of the IP sensors and the module further comprise mating connectors so that the conductive loops may be connected and disconnected from the module; the signals generated by the module in response to each IP sensor comprise digital data encoding the frequency of an oscillator responsive to the inductance of the conductive loop of the IP sensor, the frequency being encoded with errors of 100 (or 10) ppm or less;
In second aspects of the third embodiment, the signals generated by the module in response to each IP sensor comprise signals of variable frequency, the frequency being responsive to the inductance of the conductive loop of the IP sensor; the microprocessor unit further comprises circuitry for deriving digital data from the variable-frequency signals generated from each IP sensor, the digital data comprising encoding of the variable frequency of the signals with errors of 100 ppm or less; the microprocessor unit further comprises multiplex circuitry for permitting single deriving circuitry to derive digital data from a plurality of variable-frequency signals.
In a fourth embodiment, the present invention includes a monitoring apparatus for non-invasively monitoring physiological parameters of an individual comprising: a monitoring garment comprising a shirt for the torso of the individual to be monitored, one or more inductive plethysmographic (IP) sensors, each IP sensor comprising an inductance sensor including at least one flexible conductive loop arranged to closely encircle the torso, wherein the inductance of the conductive loop is responsive to the cross-sectional area of the torso enclosed by the loop, a cardiac timing sensor for generating signals responsive to occurrence of cardiac ventricular contractions, a signal cable for carrying signals directly from the conductive loops of the IP sensors and for carrying signals from the sensor, electronic circuitry comprising (i) a multiplexing switch for connecting the conductive loop of any one of the IP sensors to an oscillator, the oscillator having an oscillation frequency responsive to the inductance of the conductive loop connected by the multiplexing switch, and (ii) a demodulator operatively coupled to the oscillator and outputting digital data responsive to the oscillation frequency, and a microprocessor unit comprising a microprocessor for receiving signals from the signal cable and for receiving digital data from the electronic circuitry and for recording digital data from received inputs in a removable computer-readable memory media.
In first aspects of the fourth embodiment, the digital data responsive to the oscillation frequency has errors of 100 (or 10) ppm or less; the electronic circuitry is housed in the microprocessor unit; the resistance of the data signal cables and the multiplexing switch from the conductive loop of any IP sensor to the oscillator is less than 1 xcexa9; the multiplexing switch is controlled so that oscillator is periodically connected to the conductive loop of each IP sensor for the duration of a sampling period (1 msec or less).
In second aspects of the fourth embodiment, the digital data output by the demodulator comprises digital data encoding a count of a number cycles of the oscillator occurring within a sampling period and digital data encoding a count of a number of periods of a clock occurring within the counted oscillator cycles; the microprocessor unit further comprises a memory accessible to the microprocessor, and wherein the memory comprises encoded software instructions for causing the microprocessor to determine the actual oscillator frequency by dividing the count of the number of oscillator cycles by the count of the number of clock periods; the memory further comprises software instructions for causing the microprocessor to determine an more accurate frequency by combining the counts of a plurality of sampling periods.
In a fifth embodiment, the present invention includes a monitoring apparatus for non-invasively monitoring physiological parameters of an individual comprising: a monitoring garment comprising a shirt for the torso of the individual to be monitored, a plurality of sensors, the sensors comprising (i) one or more inductive plethysmographic (IP) sensors, each IP sensor comprising an inductance sensor including at least one flexible conductive loop arranged to closely encircle the torso, wherein the inductance of the conductive loop is responsive to the cross-sectional area of the torso enclosed by the loop wherein at least one sensor comprises a transmitter for wirelessly transmitting signals generated by the sensor within the vicinity of the physiological monitoring apparatus, a microprocessor unit comprising (i) a receiver for receiving signals wirelessly transmitted from the sensors, and (ii) a microprocessor for accepting the received signals and for recording digital data derived from the received signals in a removable computer-readable memory media.
In first aspects of the fifth embodiment, at least one sensor generates output signals in a digital form, and wherein the transmitter transmits the generated digital signals; the transmitter and the receiver conform to the Bluetooth standard; at least one sensor generates variable-frequency analog output signals, and wherein the transmitter output is modulated by generated variable-frequency analog signal; all sensors comprise a transmitter for wirelessly transmitting signals generated by the sensor within the vicinity of the physiological monitoring apparatus.
In second aspects, the fifth embodiment further comprises a signal cable, wherein the output of at least one sensor is carried to the microprocessor unit by a signal cable, and wherein the microprocessor records digital data derived from signals carried by the signal cable; the sensors further comprise a cardiac timing sensor for generating signals responsive to occurrence of cardiac ventricular contractions.
In a sixth embodiment, the present invention includes a system for the non-invasive physiological monitoring of physiological parameters of at least one individual comprising: at least one physiological monitoring apparatus comprising a monitoring garment worn on the torso of an individual being monitored, wherein the monitoring apparatus stores in a digital form in a removable computer-readable memory media data, wherein the data is by sensors comprising generated from (i) one or more inductive plethysmographic (IP) sensors flexibly attached to the monitoring garment, and (ii) a cardiac timing sensor for generating signals responsive to cardiac ventricular contractions, and a data repository for reading data from the removable computer-readable memory media that has been recorded by the physiological monitoring apparatus and for storing read data in a data archive, the data repository being remotely located from the physiological monitoring apparatus.
In first aspects of the sixth embodiment, the physiological monitoring apparatus further transmits data wirelessly, and wherein the data repository further receives data wirelessly that has been transmitted by the physiological monitoring apparatus, and then stores the received data; the physiological monitoring apparatus further comprises a microprocessor for processing the generated data for determining physiological events and alarms, and wherein the data wirelessly transmitted comprises the determined physiological events and alarms.
In second aspects, the sixth embodiment further comprises a local data repository co-located with the physiological monitoring apparatus, wherein the local data repository receives data wirelessly transmitted by the physiological monitoring apparatus and stores received data in a local data archive, and wherein the local data repository comprises display terminals for making stored data available to local health care professionals; the data repository further comprises display terminals for making stored data available to health care professionals and to users monitoring the operation of the system.
In third aspects, the sixth embodiment, further comprises a plurality of physiological monitoring apparatus, each apparatus for monitoring a different individual, and wherein the data repository reads data from removable computer-readable memory media recorded by the plurality of physiological monitoring apparatus.
In a seventh embodiment, the invention further includes a computer readable medium comprising data recorded in digital form, wherein the recorded digital data comprises data responsive with errors of 100 ppm or less to the frequency of an oscillator connected to at least one conductive loop of at least one inductive plethysmographic sensor; and also encoded software for causing microprocessors, data repositories, and the like to perform the described methods.